Concentration and risk (Tables)

12 Months Ended

Dec. 31, 2014

Concentration and risk [Abstract]

Concentration of credit risk

	As of December 31,
	2013			2014
Mobile telecom operator 1		60	%		30	%
Mobile telecom operator 2		20	%			*
Mobile telecom operator 3		17	%			*

* Less than 10% 

Concentration of game revenues

	For the year ended December 31,
	2012			2013			2014
Game 1			*		42	%		11	%
Game 2		60	%		33	%			*
Game 3			*		11	%		13	%
Game 4		20	%			*			*
Game 5		12	%			*			*

* Less than 10%